Java — 108 Operations for AI Agents

This page is the canonical reference an AI coding agent uses to refactor, query, and analyze Java code through the act MCP server. 108 operations available: 63 refactor, 15 query, 30 analysis. Each operation is callable from Claude Code, Cursor, Codex, OpenCode, or any MCP-compatible agent host. Click any operation for a stable anchor link suitable for citation.

15Query
63Refactor
30Analysis

Query

OperationDescription
callersFind every call site of a function or method across the codebase. Use to understand who depends on a function before changing its signature. Requires LSP. Params: symbol (string) [, file (string)]
control_flowGet a function's control flow — branches, loops, early returns, and basic blocks in execution order. Use to understand complex logic without reading the full implementation. Params: target (string), file (string)
definitionJump to definition — find where a symbol is defined given a usage location. Uses abstract syntax trees by default, no LSP required. Params: symbol (string), file (string), line (u32), column (u32)
diagnosticsGet compiler errors and warnings from the language server. Omit `file` for workspace-wide diagnostics. Pass a file path or directory path to scope results. Requires LSP.
fix_autoAuto-fix all deterministic issues in a file, directory, or workspace — missing imports, unused imports, simple type errors. Runs multiple fix-revalidate cycles. Use after making changes to clean up automatically. Requires LSP. Params: none [, file (string), workspace_mode (bool), category (string), commit (bool), max_rounds (u32)]
get_typeGet the compiler-inferred type of any expression at a position. Use to understand types without reading surrounding code. Requires LSP. Params: file (string), line (u32), column (u32)
graphBuild a dependency graph from a file — trace what it imports and what imports it, across multiple hops. Use to understand module relationships and change impact before refactoring. Params: file (string) [, depth (u32), direction (string), leaves (bool), order (string)]
import_organizeOrganize, sort, and deduplicate imports in a file. Removes unused imports. Use after adding new code or moving symbols to clean up import blocks automatically. Params: file (string) [, preview (bool)]
interfaceGet a symbol's public API — signatures, types, and docstrings without implementation bodies. Like skeleton but for a single symbol. Use to understand how to call something without reading its internals. Params: target (string), file (string) [, include_private (bool)]
mutationsIdentify side effects — what external state a function reads or writes (globals, file I/O, network, etc.). Use to understand if a function is pure or has hidden dependencies. Params: target (string), file (string)
referencesFind every usage of a symbol across the entire codebase — all files, not just the current one. Use before renaming, refactoring, or deleting to understand full impact. Requires LSP. Params: symbol (string), file (string)
repo_outlineGet a compressed overview of the entire repository in one call — file tree with languages, line counts, and optionally symbol names per file. Orders of magnitude cheaper than listing directories and reading files individually. Params: none [, path (string), depth (u32), include (glob), exclude (glob), symbols (bool), max_files (u32), relative (bool)]
skeletonGet a file's structure — function signatures, class declarations, type definitions — without implementation bodies. Use INSTEAD of reading the full file to understand its API. Typically 5-10x fewer tokens than reading the raw file. Params: file (string)
symbolsList all symbols (functions, classes, variables, types, constants) defined in a file with their locations and kinds. Use INSTEAD of reading a file when you need to know what's defined in it. Much cheaper than reading the full file. IMPORTANT: file must be a path to a single source file — never a directory or empty string. Params: file (string)
symbols_batchRetrieve symbols from multiple files in a single call. Use instead of calling symbols() in a loop — one request instead of N. Params: none [, files (string[]), ids (string[]), kinds (string[])] — provide files or ids

Refactor

OperationDescription
add-final-modifierAdd final modifier for immutability
add-interface-implementationAdd interface implementation to a class
add-null-checkWrap expression in null-check guard
add-parameter-from-fieldAdd a method parameter sourced from a field
add-static-modifierAdd static modifier when applicable
add-visibility-modifierAdd explicit public/private/protected modifier
change-method-signatureModify a method's parameter list or return type
convert-anonymous-class-to-lambdaConvert single-method anonymous class to lambda
convert-anonymous-to-classExtract an anonymous class into a named top-level or nested class
convert-enhanced-forConvert traditional for to enhanced for loop
convert-if-to-ternaryConvert if-else to ternary operator
convert-string-concat-to-builderConvert string concatenation in loops to StringBuilder
convert-to-builderGenerate a Builder pattern for a class
convert-to-enumConvert a class with constant fields to an enum
convert-to-lambdaConvert anonymous inner class to lambda
convert-to-object-initializerReplace constructor chaining with an object initializer block
decrease-visibilityDecrease visibility for encapsulation
encapsulate-fieldMake a field private and generate getter/setter
expand-visibilityWiden the visibility modifier of a declaration
extract-classExtract inner class to file-level class
extract-interfaceExtract method signatures into new interface
extract-methodExtract code block into new method
extract-superclassPull common members into a new superclass
extract-variableExtract expression into new local variable
extract_functionExtract a code selection into a new function — automatically infers parameters, return types, and inserts the call site. Use instead of manually cutting/pasting code. Works without LSP; LSP improves type inference. Params: file (string), new_name (string), start_line (u32), start_column (u32), end_line (u32), end_column (u32) [, preview (bool)]
extract_variableExtract an expression into a named variable — inserts the declaration and replaces the expression with the variable name. Works without LSP. Params: file (string), new_name (string), start_line (u32), start_column (u32), end_line (u32), end_column (u32) [, preview (bool)]
generate-constructorCreate constructor with field initialization
generate-equals-methodGenerate equals() and hashCode() implementation
generate-getterCreate getter method for field
generate-getters-settersCreate both getter and setter for field
generate-implementationCreate class implementing interface
generate-javadocCreate javadoc comment block
generate-override-annotationAdd @Override annotation to overridden methods
generate-setterCreate setter method for field
generate-tostring-methodCreate toString() implementation
generify-variableReplace a raw type variable with a generic type parameter
increase-visibilityIncrease visibility when needed
inlineInline a variable, function, or method — replace every usage with its definition body, then remove the original. The inverse of extract. Works without LSP (single-file); LSP enables cross-file inlining. Params: file (string), symbol (string) [, line (u32), preview (bool)]
inline-methodReplace method call with method body
inline-variableReplace variable with its assignment
insert_bodyReplace a function's implementation body with new code. AST-validated — rejects if the result has parse errors, so you can't accidentally break syntax. Use instead of manual text editing for function rewrites. Params: file (string), symbol (string), code (string) [, commit (bool)]
introduce-interfaceExtract a new interface from an existing class
introduce-methodWrap statements into new method
introduce-parameterConvert local variable to method parameter
introduce-variableExtract an expression into a named local variable
merge-variable-declarationMerge a variable declaration and its first assignment into one statement
move-method-upMove a method to the superclass
move_symbolMove a function, class, or type to a different file and automatically update all imports across the codebase. Use instead of manually cut/paste + fixing imports. Works without LSP (single-file); LSP enables cross-file import updates. Params: file (string), symbol (string), destination (string) [, preview (bool)]
organize-importsSort and deduplicate import statements
pull-up-methodPull a method from a subclass into the superclass hierarchy
push-down-methodMove a method from a superclass down to subclasses
remove-redundant-castDelete unnecessary type cast
remove-redundant-modifiersDelete modifiers that are implied by context
remove-unused-fieldDelete field that is never read
remove-unused-importDelete unused import statement
remove-unused-methodDelete method that is never called
renameRename a symbol and automatically update ALL references across the codebase. Safer and faster than find-and-replace — AST-aware, won't rename strings or comments. Works without LSP (single-file); LSP enables cross-file renames. Params: file (string), old_name (string), new_name (string) [, line (u32), column (u32), preview (bool)]
renameRename symbol and all references
reorder-parametersChange the order of method parameters
simplify-field-initializationMove a field initializer from the constructor into the field declaration
simplify-lambdaConvert a verbose lambda to a method reference where possible
split-variable-declarationSplit a combined variable declaration and assignment into separate statements
wrap-method-bodyWrap a method body in a try/catch, synchronized, or other block

Analysis

OperationDescription
analyze_chokepointsFind files that act as critical bottlenecks — high betweenness centrality in the dependency graph (R4). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_clustersIdentify tightly coupled groups of files using community detection. Use to discover natural module boundaries and understand which files change together. Params: none [, granularity (string), min_size (u32), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_cohesionMeasure intra-module cohesion for each file — ratio of internal to total symbol edges (H2). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_couplingMeasure coupling per file — how many files depend on it (afferent) vs how many it depends on (efferent), plus instability and abstractness scores. Use to find the most critical/fragile files. Params: none [, granularity (string), sort (string), threshold (f64), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_cycle_riskScore each circular dependency cycle by its external risk surface (R6 circular risk zones analysis). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_cyclesFind circular dependency chains in the codebase. Use to identify import cycles that cause build issues or indicate architecture problems. Params: none [, granularity (string), max_length (u32), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_dead_codeFind dead code — functions, classes, and types that are never referenced from any entry point. Use before cleanup to safely identify what can be deleted. Params: none [, entry (string[]), granularity (string), include_tests (bool), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_depthCompute longest transitive dependency chain per file (S4 dependency depth analysis). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_entry_pointsDetect entry points: main functions, HTTP routes, CLI commands, event listeners, test files (S5). Params: none [, include (string[]), exclude (string[])].
analyze_exportExport the full semantic graph (files, symbols, dependencies) in JSON, DOT (Graphviz), or CSV format. Use for visualization or external analysis. Params: none [, format (string), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_extractionScore clusters for service or package extraction viability (M2 extraction candidates analysis). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_fan_balanceCompute fan-in/fan-out imbalance for migration ordering guidance (M6 fan balance analysis). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_featuresInventory language-specific AST features used in the codebase — async, generics, decorators, etc. (M3). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_hotspotsRank files by composite complexity score — max cyclomatic complexity, statement count, nesting depth (H1). Params: none [, top_n (u32), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_impactCompute change impact for a target file — finds all files directly and transitively depending on it (R1). Params: target (string) [, max_depth (u32), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_inconsistenciesDetect inconsistent abstractions — sibling files in the same directory that diverge from the group's structural pattern (H5). Params: none [, include (string[]), exclude (string[])].
analyze_inheritanceDetect tangled inheritance — deep hierarchies (>N levels) and diamond inheritance (H6). Params: none [, include (string[]), exclude (string[])].
analyze_interface_bloatDetect interface bloat — files where the public API is disproportionately large relative to implementation (H3). Params: none [, include (string[]), exclude (string[])].
analyze_interfacesMap cross-module interfaces — symbols that cross directory-module boundaries, ranked by interface width (M4). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_layersDetect architectural layers from directory names and find dependency direction violations (S1+S2). Params: none [, detect_only (bool), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_orphan_typesFind type definitions used exclusively outside their defining directory (H4 orphan types analysis). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_patternsFind code smells — god functions, deep nesting, high coupling, and other structural issues. Use to identify refactoring targets or assess code quality. Params: none [, tier (string), pattern (string), file (string), severity (string), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_platform_depsDetect platform-specific API usage by scanning imports (M5 platform dependencies analysis). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_readinessCompute migration readiness scores per file — composite of complexity, coupling, porting blockers (M1). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_rolesClassify files by architectural role: entry point, routing, business logic, data access, config, test, utility, types, generated (S3). Params: none [, include (string[]), exclude (string[])].
analyze_seamsFind the natural boundaries between file clusters — the narrowest points where groups of files communicate. Use to identify where to split modules or add API boundaries. Params: none [, min_cluster_size (u32), max_seam_width (u32), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_stabilityCompute stability index (R2) and detect stable dependency violations (R3) — flags edges where stable modules depend on unstable ones. Params: none [, index_only (bool), include (string[]), exclude (string[])].
analyze_surfaceMeasure API surface area — count exposed functions, types, and complexity at a module boundary. Use to assess whether an API is too large or leaky. Params: none [, boundary (string), files (string), include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_test_gapsDetect source files with no or partial test coverage based on graph import analysis (R5). Params: none [, include (string[]), exclude (string[])]. Use include/exclude to restrict the scan scope (e.g. include=["crates"], exclude=["corpus"]).
analyze_type_completenessAnalyze type boundary completeness — detect 'any' types, untyped parameters, missing return types at exported function boundaries (M7). Params: none [, include (string[]), exclude (string[])].
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